Modern technology has provided various types of plastic pipe which have replaced the more expensive metal pipes and tubings used in residential plumbing and water supplies. These new materials are generally easier to work with than their metal counterparts but necessitate gluing of the joints. Unfortunately the failure rate of glued joints is relatively high.
To repair a glued joint in a plastic pipe requires that the joint be cut out of the pipe string and replaced by a short section with two couplings or if the leak is relatively small by a welding process which includes melting a plastic material along the edge of the coupling. To accomplish either method of repair, fluid must be removed from the pipe line. This process can be extremely time consuming and costly.